1. Field of the Invention
The present invention relates to the recovery of oxygen which is formed by hydrogen peroxide decomposition during the epoxidation of an olefin such as propylene with hydrogen peroxide as well as recovery of associated olefin.
2. Description of the Prior Art
Methods are known for the molecular oxygen oxidation of a secondary alcohol to form hydrogen peroxide. See, for example, U.S. Pat. Nos. 2,871,101-2,871,104. See also copending application Ser. No. 08/268,891 filed Jun. 30, 1994.
Methods are also known for the catalytic epoxidation of olefins such as propylene with hydrogen peroxide to produce an alkylene oxide such as propylene oxide. See, for example, U.S. Pat. Nos. 4,833,260 and 5,262,550 as well as copending application Ser. No. 08/310,546 filed Sep. 22, 1994, the disclosure of which is incorporated herein.
As described in copending application Ser. No. 08/310,546, there is some hydrogen peroxide decomposition which takes place during the epoxidation with the formation of oxygen and this formed oxygen can be purged from the epoxidation reaction zone with, for example, propylene vapor in order to avoid the formation of hazardous mixtures.
In order to avoid a substantial economic penalty, it is important that the purge gas mixture from the epoxidation zone be safely and effectively treated for the recovery of the various components.